The application describes a pilot test of a text-messaging smoking cessation intervention for pregnant women. Despite the great health benefits associated with smoking cessation in pregnancy to both mother and baby, few studies to date have examined the applications of text messaging or other communication technologies for smoking cessation in this population. This research application will explore how a state-of-the-art, interactive and intensive, text messaging program, Quit4Baby, can promote smoking cessation in pregnant smokers. The study Aims are: 1) To elicit qualitative feedback from pregnant smokers (n=20) about the concept of Quit4Baby, the proposed message protocols in Quit4Baby, and the proposed messages in Quit4Baby; 2) To develop a prototype of Quit4Baby which is consistent with Clinical Practice Guidelines (DHHS 2008), and 3) To conduct a formative evaluation of Quit4Baby 1.0 with pregnant smokers (n=120). Smokers will be randomized to Text4Baby or Text4Baby enhanced with Quit4Baby 1.0. It is hypothesized that Text4Baby enhanced with Quit4Baby 1.0 will be acceptable to pregnant smokers. Furthermore, it is hypothesized that Text4Baby enhanced with Quit4Baby 1.0 will result in greater improvements in the cognitive determinants of quitting and more favorable quitting outcomes. Participants will be interviewed at baseline, 1 and 3 months after enrollment. This study is important because currently a majority of pregnant smokers do not receive smoking cessation counseling and new treatment modalities are needed. The proposed research is innovative because (1) it builds a new bridge between established programs in text messaging for smoking cessation, pregnancy smoking cessation, and educational text messaging to pregnant women; (2) it has the potential to increase the reach of smoking cessation programs that are specifically targeted to pregnant smokers; and (3) it provides a new approach in the design and delivery of pregnancy smoking cessation programs. This study is consistent with the stated mission of the NIH and the NCI to build a knowledge base around effective methods for pregnancy smoking cessation and is consistent with the goals of Healthy People 2020 to increase rates of smoking cessation among pregnant women. If found to be promising, additional funding will be sought for the further development and rigorous testing of Quit4Baby among a larger population of pregnant smokers.